Vectran is an extremely strong and light synthetic fiber similar in property and performance to Aramid/Kevlar, yet is far more flexible for reduced rolling resistance and holds its high strength and puncture-resistant properties better in wet conditions

The Grand Prix 4000 road bicycle tires have a highly technically advanced tread compound that uses an Activated Silica as a filler. This compound is unique in the use of saline to increase binding of the silica to the rubber. The result is a compound that is extremely low in rolling resistance and has outstanding grip in dry conditions.

I bought these expecting awesome things from this tire, but was disappointed. It developed cuts quickly. I had a set of Vittoria tires (can't remember the specific brand) before this that were half the price (though more rolling resistance and therefore slower), but were way more reliable and lasted a lot longer. I think this tire is more designed for the cyclist who wants a beautiful smooth ride (which this gave) but who also is willing to fork out beaucoup bucks for a tire that won't last very long.

These tires came on some HED Jet 5 wheels that I purchased and are the tires that HED did aero test s with. First thing I noticed is the significantly better grip when you run your finger across them so that is a plus. Have used them under racing conditions and am very pleased. These holding up well and will buy these as replacements when the time comes.

The shock absorption is amazing. You will be astounded by the Improvment of the ride quality delivered by this tire! Riding on the same road surface before I mounted the continental tires, I would get a flat about every two weeks of riding, now, NO FLATS!Great tire!

I have 2 road bikes and have used Continental Grand Prix's for the last 4-5 replacement cycles. They seem to last nearly forever so I have been riding Conti's for over 10 years. In that time I have had, maybe, 3 flats. Meanwhile they roll noticeably easier that other brands I have tried. So, while relatively expensive, they prove themselves a worthy investment in performance and durability. I expect the "4000's" will prove even better that the last generation - the "3000" series.

Finally, Bike Nashbar's price made the choice a no brainer for my recent replacement.

Continental 4000 tires put to shame all other tires I have tried. I only use the S series with black chili rubber but non chili rubber I am sure is good as the 2nd best tire I have ever used is the Continental Ultra Race folding. I have tried Hutchinson, Vredestein, Michelin and they are not in the same league. The rolling resistance, puncture resistance, durability, dry grip, wet grip, and ride quality are all noticeably better than any other tire. The Schwalbe Ultremo series I have not tried and they are the only tires that may be in the same league. The Vittoria Diamante and the EVO I also haven't tried and they are surely decent tires as I like the Rubino Pro's and the Zaffiro Pro's for value tires. The Mavic tires, which I understand are made by Vittoria, are very nice tires too. The Michelin Pro's seem very over rated tires to me and any Michelin owner who tries Conti's will be converted, I guarantee on the 1st ride. Those who complain about flats with Conti's to are just extremely unlucky because the flat resistance of the Grand Prix from my experience is nothing less than sensational. No flats in 4 years of using them and the Ultra Race too. The Grand Prix 4 Season and Gatorskins are of course decent tires but you lose so much speed and ride quality for a little improvement in puncture resistance.

I read some where in the reviews that one of the tires exploded. I had that happen to me, took to the bike shop where I purchased it. I only had 100 miles on it or so, the Tech told showed me why. These are directional tires and if you put them on rotating the wrong way, thats what happens. I have had great success with these tires, I have had 1 flat in over 3500 miles. They are ready to be changed here in the next week. I will not use any tire other than these. Great tire. I ride 150 to 250 miles a week.